#include <stdio.h>

int euclid(int a,int b)
{
 int c;
  while (b)
   {
    c = a % b;
    a = b;
    b = c;
   }
  return a;
}
int main()
{
  long n,s;
  FILE *f,*g;
  f=fopen("fractii.in","r");
  g=fopen("fractii.out","w");
  fscanf(f,"%li",&n);
  s=2*n-1;
  for (int i=2;i<=n;i++)
   for (int j=i+1;j<=n;j++)
    if (euclid(i,j) == 1) s += 2;
  fprintf(g,"%li",s);
  fclose(g);
  fclose(f);
  return 0;
}